The Key Card is designed so that you can keep some keys in your wallet instead of on your key ring. I came up with this design so that I don't have to keep a key ring or keys on my car key-fob. I just put the keys that I need in my slim wallet. My car is key-less so I have no keys poking into my legs anymore!

There are three different cards; they have one, two, and three holes respectively. The card thickness should be just barely thicker than a SC1 key, and should fit pretty tight into place. The key-holes are modeled after the SC1 Key design (got mine at Lowe's). I do not know if any different key types will work, and I do not currently have any other key types to try. I have no idea if I will try to model any different key holes. I modeled the entire thing in AutoCAD, and included the DWG files of the card and Key cut-outs if anyone wants to remix the keyholes without re-doing the entire thing.